The baryonic mass measured from the early Universe through CMB observations makes up only the ~5% of the Universe. Hydrodynamical simulations suggest that the initial density fluctuations form filament-like structures also known as cosmic webs at later times. Clusters of galaxies are found in the dense knots of these cosmic webs. Detecting these filaments, connecting the clusters of galaxies in the late universe is challenging since the expected densities are extremely low. However, density and therefore the emission is expected to be enhanced in the regions where two clusters are nearby, and such systems are detected rarely. The proximity of the A3391-A3395 galaxy clusters and hosting a galaxy group in between provides a perfect laboratory to study this emission. The previous effort was made using X-Ray telescopes such as XMM-Newton, Chandra, and SUZAKU and also through Sunyaev Zeldovich effect using Planck data. Most robust data recently came from eROSITA not only showing the emission from the bridge between the clusters but also several other extended X-ray emission surrounding the system. In order to draw conclusive results, optical follow-ups on the system are required. I will provide the information on the existing redshifts on the cluster region and the results from currently studied optical data from the Dark Energy Camera (DECam) on the BLANCO telescope. I will also present the measured photometric redshifts and possible optical counterparts of the extended objects detected in X-Ray with eROSITA.
|Presenter status||eROSITA consortium member|